NEHRP Clearinghouse

National Science Foundation, Washington, D.C. Div. of Advanced Environmental Research and Technology.,
July 1977,
218 p.

Identifying Number(s)

R77-22

Abstract

By using random vibration theory and an approximate first passage problem solution, a method is developed for obtaining distributions of responses of elastic multidegree-of-freedom systems to earthquake excitation. Uncertainty in both dynamic model and earthquake excitation parameters is accounted for. Factors contributing to uncertainty in the strength measures used for rigid frame buildings are examined. A simple frame is designed by elastic criteria and a second moment description of the story strength measures is given. By using the desired load effect and strength distributions and by incorporating seismic risk information, the probability of failure is computed. Alternate elastic seismic design strategies are reviewed and their interrelationships are clarified.